Recording medium, method of creating file of the recording medium, and method and apparatus for reproducing the same

ABSTRACT

A recording medium, a method of creating a file of the recording medium, and a method and apparatus for reproducing the same are disclosed, wherein position change and transition of random playback points among title recorded within the recording medium can be easily performed, thereby providing an apparatus having more convenient title playback functions to the users. The method of creating a file of the recording medium includes forming a PlayList file including playback control information of a set of recorded data, forming an object file including an execute command of the PlayList file, and forming an index file including a set of Normal Title information designating a specific object within the object file, and a set of auxiliary Title information designating a random point of data being reproduced by the Normal Title information.

This application claims the benefit of the Korean Patent Application No.10-2003-0090094, filed on Dec. 11, 2003, which is hereby incorporated byreference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recording medium, and moreparticularly, to a recording medium, a method of creating a file of therecording medium, and a method and apparatus for reproducing the same.

2. Discussion of the Related Art

Optical discs are widely used as a recording medium for recording massdata. Presently, among a wide range of optical discs, a new high densityoptical recording medium, such as a blu-ray disc (hereinafter referredto as “BD”), is under development for recording (or writing) and storinghigh definition video and audio data for a long period of time.Currently, an optical recording and/or reproducing apparatus forrecording and/or reproducing the blu-ray disc (BD), which is known to bethe next generation recording medium technology, is under development asa next generation optical recording solution that is capable of havingdata significantly surpassing the conventional DVD, along with manyother digital apparatuses.

More specifically, in order to reproduce data recorded within theabove-described blu-ray disc (BD), a systematic set of file information(or file structure) for controlling data and, also, controlling a methodof reproducing data should be provided. However, in the current blu-raydiscs (BDs), a preferable method for creating the file information hasnot yet been proposed, and so there lies many limitations in developinga blu-ray disc (BD)-based optical recording and/or reproducingapparatus. And eventually, such limitations lead to difficulty inreproducing the data recorded within the blu-ray disc (BD) by usingvarious methods, and in reproducing the recorded data in accordance withthe users' demands.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a recording medium, amethod of creating a file of the recording medium, and a method andapparatus for reproducing the same that substantially obviate one ormore problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a recording medium, amethod of creating a file of the recording medium, and a method andapparatus for reproducing the same, wherein file information forcontrolling data recorded within the recording medium are newly defined,and more specifically, wherein systematized index files and object filesare provided.

Another object of the present invention is to provide a recordingmedium, a method of creating a file of the recording medium, and amethod and apparatus for reproducing the same, wherein, whenplaying-back a plurality of titles that are recorded within therecording medium, a plurality of sets of auxiliary Title information areincluded within an index file, thereby enabling transition betweentitles to be carried out at a random point.

A further object of the present invention is to provide a method andapparatus for reproducing a recording medium with more efficiency byusing the newly created file information.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, amethod of creating a file for a recording medium includes forming aPlayList file including playback control information of a set ofrecorded data, forming an object file including an execute command ofthe PlayList file, and forming an index file including a set of NormalTitle information designating a specific object within the object file,and a set of auxiliary Title information designating a random point ofdata being reproduced by the Normal Title information.

In another aspect of the present invention, a method of creating a filefor a recording medium includes forming an index file for playing-backat least two titles within the recording medium including the at leasttwo titles, wherein the index file includes a plurality of sets ofNormal Title information, wherein each set of the Normal Titleinformation is in a one-to-one correspondence with each of the at leasttwo titles recorded within the recording medium, and at least one set ofauxiliary Title information enabling playback of another title to beperformed starting from a random point of the title, while playing-backa specific title by using a specific set of the Normal Titleinformation.

In another aspect of the present invention, a recording medium includesa stream area having at least two titles recorded therein, and a filerecording area having an index file for playing-back the at least twotitles, wherein the index file includes a plurality of sets of NormalTitle information, wherein each set of the Normal Title information isin a one-to-one correspondence with each of the at least two titlesrecorded within the recording medium, and at least one set of auxiliaryTitle information enabling playback of another title to be performedstarting from a random point of the title, while playing-back a specifictitle by using a specific set of the Normal Title information.

In another aspect of the present invention, a method for reproducing arecording medium includes playing-back a first title by using a set ofNormal Title information, and shifting to a random point of a secondtitle by using a set of auxiliary Title information, during the playbackof the first title, thereby reproducing the second title starting from acorresponding shifted point of the second title.

In a further aspect of the present invention, an apparatus forreproducing a recording medium includes an optical recording and/orreproducing unit playing-back at least one title recorded within astream area of the recording medium, and reading a set of Normal Titleinformation and a set of auxiliary Title information recorded within afile recording area of the recording medium, and a controllercontrolling the optical recording and/or reproducing unit, so as toplay-back one of the titles recorded within the recording medium byusing the Normal Title information, and to play-back another titlestarting from a random point by using the auxiliary Title information.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiments of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 illustrates a file structure being recorded on an optical disc,the optical disc being a recording medium, according to the presentinvention;

FIG. 2 illustrates a data recording structure being recorded on theoptical disc, the optical disc being the recording medium, according tothe present invention;

FIGS. 3A and 3B illustrate general views of a file structure that isrecorded within an optical disc according to the present invention, theoptical disc being a recording medium, and, more particularly, of aNormal Title and an auxiliary Title according to the present invention;

FIG. 4 illustrates a method of playing-back an optical disc fileaccording to a first embodiment of the present invention;

FIG. 5 illustrates a method of playing-back an optical disc fileaccording to a second embodiment of the present invention; and

FIG. 6 illustrates an optical recording and/or reproducing apparatusaccording to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts. In addition,although the terms used in the present invention are selected fromgenerally known and used terms, some of the terms mentioned in thedescription of the present invention have been selected by the applicantat his or her discretion, the detailed meanings of which are describedin relevant parts of the description herein. Furthermore, it is requiredthat the present invention is understood, not simply by the actual termsused but by the meaning of each term lying within.

In this detailed description, “recording medium” refers to all types ofmedium that can record data and broadly includes all types of mediumregardless of the recording method, such as an optical disc, a magnetictape, and so on. Hereinafter, for simplicity of the description of thepresent invention, the optical disc and, more specifically, the “blu-raydisc (BD)” will be given as an example of the recording medium proposedherein. However, it will be apparent that the spirit or scope of thepresent invention may be equally applied to other types of recordingmedium.

FIGS. 1 and 2 respectively illustrate a file structure and a datarecorded structure being recorded within an optical disc according tothe present invention, wherein the optical disc is a recording medium.More specifically, FIG. 1 illustrates a file structure controllingstream data recorded within the optical disc according to the presentinvention, wherein the optical disc is a recording medium. Herein, atleast one BD directory (BDMV) is included in a root directory (root).Each BD directory includes an index file (index.bdmv) and an object file(MovieObject.bdmv), which represent general files that are used wheninteracting with one or more users. For example, the index file containsdata representing an index table which includes diverse informationregarding a plurality of selectable menus and titles.

Each BD directory includes three file directories including data to bereproduced, and information required for reproducing the data. The filedirectories included in each BD directory are a stream directory(STREAM), a playlist directory (PLAYLIST), and a clip informationdirectory (CLIPINF). The index file and the object file being thegeneral files, which are more closely related to the present invention,will be described in detail in a later process.

The stream directory includes audio/video (AV) stream (hereinafterreferred to as “AV stream”) files. More specifically, the stream files(01000.m2ts, 02000.m2ts) may generally be in the form of MPEG2 transportpackets and be named as “*.m2ts”. Further, the clip informationdirectory (CLIPINF) includes clip information files (01000.clpi,02000.clpi) being in one-to-one correspondence with the stream files(*.m2ts) included in the stream directory. A clip information file(*.clpi) records property information and timing information of acorresponding stream file (*.m2ts), wherein the timing informationincludes mapping information that maps presentation time stamp (PTS)with source packet number (SPN) using entry point map. In the BDstandard, each pair of a stream file (*.m2ts) and its corresponding clipinformation file (*.clpi), which are in one-to-one correspondence withone another, is designated as a clip. For example, 01000.clpi includedin CLIPINF includes the property and timing information of 01000.m2tsincluded in STREAM, and 01000.clpi and 01000.m2ts form a clip.

Referring back to FIG. 1, the playlist directory (PLAYLIST) includes oneor more PlayList files (*.mpls), wherein each PlayList file (*.mpls)includes at least one PlayItem which designates playing interval for aspecific original clip. More specifically, a PlayItem includesinformation designating presentation start and presentation end times(IN-Time and OUT-Time) for reproduction of a specific original clip,which may be designated by clip_Information_File_name within thePlayItem. Accordingly, a PlayList file (*.mpls) represents a basicplayback control file for playing-back a desired clip from a combinationof one or more PlayItems.

Moreover, the above-described BD directory (BDMV) includes an index file(index.bdmv) and an object file (object.bdmv), which are general filesfor ensuring user interactivity. Most particularly, at least one of aplurality of title information that can be selected by the user isprovided in the index file (index.bdmv). And, the object file(object.bdmv) file includes a plurality of objects (OBJ), wherein eachof the objects (OBJ) includes a PlayList file playback command (e.g.,Play PlayList), which is associated with a playback of the specifictitle. Accordingly, at least one of the object files (Object.bdmv) isprovided in the present invention. And, in case a plurality of objectmodes is provided depending upon the attributes of the data, the objectfiles (Object.bdmv) may include a movie object file (MovieObject.file),a Java object file (JavaObject.file), and a web object file(WebObject.file).

Also, when creating the index file according to the present invention,the index file includes different types of title information, such asNormal Title information and auxiliary Title information. Morespecifically, the Normal Title information can be recognized by theuser, and the auxiliary Title information supplements the Normal Titleinformation but is not recognized by the user. The Normal Titleinformation and the auxiliary Title information will be described indetail in FIG. 3A to FIG. 6. Accordingly, newly creating fileinformation according to the present invention refers to systematizing(or organizing) the association between the files (i.e., index file,Object file, PlayList file, ClipInfo file, and stream files) includedwithin the file structure, and to newly define the information includedwithin the file, so as to support a specific playback method.

FIG. 2 illustrates information corresponding to the file structure beingrecorded within the optical disc. Starting from the inner circumference(or center) of the optical disc, the disc volume includes a file systeminformation area occupying the inmost portion of the disc volume, an AVstream area occupying the outmost portion of the disc volume, and adatabase area occupied between the file system information area and thestream data area. In the file system information area, systeminformation for controlling the entire data files is recorded. And,actual stream data such as audio/video/graphic data are recorded in theAV stream area. The PlayList files, clip information files, and generalfiles, such as the index file (index.bdmv) and the object file(object.bdmv), are recorded in the database area of the disc volume.Therefore, the user uses the file information included in the databasearea, so as to select a desired AV stream and to play-back the selectedand desired AV stream.

FIGS. 3A and 3B illustrate examples of the method of creating filesaccording to the present invention. Most particularly, FIGS. 3A and 3Billustrate interaction between the files based on the index file(index.bdmv) and the object file (object.bdmv). Accordingly, FIG. 3Aillustrates the structure of an index file (index.bdmv) and ahierarchical structure of the entire file information using a specificNormal Title information. FIG. 3B illustrates various applications ofthe Normal Title information and the auxiliary Title information withinthe index file (index.bdmv).

Referring to FIG. 3A, the index file (index.bdmv) consists of an indextable, and the index table includes title information, menu information,and first playback information. The sets of information included in theindex table are respectively linked with a corresponding specific object(OBJ) within the object file (Object.bdmv). More specifically, forexample, Normal Title #1 information within the index file includesobject identification information (OBJ_id), corresponds to the NormalTitle #1 information. In addition, the Normal Title information withinthe index table is provided to the user through a “Title search” commandfrom the user or a title menu included in the menu information.

Therefore, for example, when the user selects Title #1 among a pluralityof titles that is provided, an object #1 (OBJ #1) command is executed.Herein, object #1 (OBJ #1) is designated by Normal Title #1. The commandincludes an execute command of PlayList #1 (e.g., Play PlayList #1).Therefore, when object #1 (OBJ #1) executes PlayList #1, the clipincluding stream files related to the actual Title #1 is played-back dueto the functions and operations of the PlayList file shown in FIG. 1.Moreover, a user's “Menu Call” command executes the menu informationincluded in the index table. And, the menu information includes linkinformation (OBJ_id), which automatically connects the menu informationto a specific object (OBJ #Menu). Furthermore, the first playbackinformation included in the index table includes link information(OBJ_id), which automatically connects the first playback information toa specific object (OBJ #First-Play).

As described above, in the file structure according to the presentinvention, when executing the Normal Title information, a specificobject (e.g., OBJ #First-Play, OBJ #Menu, and OBJ #1) is automaticallyexecuted. And, the specific object includes a playback command (i.e.,Play PlayList) of the specific PlayList. Therefore, in the filestructure, as the clip file that is designated by at least on PlayItemincluded within the corresponding PlayList file is executed, the AVstream data corresponding to the title is reproduced. Therefore, thehierarchical file structure refers to a structure of the object, thePlayList, and the clip being automatically executed in series (i.e., inthe order of object→PlayList→clip) in a later process, after the userselects the Normal Title information.

The index file according to the present invention includes Normal Titleinformation and auxiliary Title information. When compared with theNormal Title information, the auxiliary Title information may bedescribed to have three main attributes. First of all, the Normal Titleinformation can be recognized by the user, and therefore, a useroperation command (also referred to as a “user operation (UO)”) executesa specific title. Although the auxiliary Title information is includedin the index file, the auxiliary Title information cannot be recognizedby the user and is automatically executed by the system (or program).However, in some particular cases, the auxiliary Title information maybe formed so as to be executed by the UO command, which will bedescribed in detail with reference to FIG. 5.

In addition, the Normal Title information includes informationdesignating a specific object (OBJ), and data (i.e., AV stream) that isrelated to the Normal Title is reproduced (or played-back) by using thedesignated specific object (OBJ). However, the auxiliary Titleinformation does not designate a specific object (OBJ) that is only usedfor the auxiliary Title information itself. More specifically, forexample, the function of the auxiliary Title information is tosupplement (or support) the playback of a specific title by using theNormal Title information.

And, finally, the title that is played-back by using the Normal Titleinformation is formed so that playback is performed by using a pluralityof objects (OBJ). Among the plurality of objects, only the startingobject (e.g., OBJ #2-1 shown in FIG. 3B) is designated by the NormalTitle information. However, the auxiliary Title information may alsodesignate the starting object that is linked by the Normal Titleinformation, as well as the subsequent object (e.g., OBJ #2-2 shown inFIG. 3B), which is linked by the starting object. More specifically, forexample, the auxiliary Title information includes informationdesignating a random object so as to play-back a specific title, whichis played-back by using the Normal Title information, staring from arandom point.

As described above, FIG. 3B illustrates the auxiliary Title informationincluded in the index file. Referring to FIG. 3B, Normal Title #2information of the index file designates a start object (OBJ #2-1),which then designates a subsequent object (OBJ #2-2) in accordance withthe hierarchical order. However the auxiliary Title #2 information mayalso be formed to directly designate the second object (OBJ #2-2) forthe Normal Title #2. Eventually, by using the auxiliary Titleinformation, the data being reproduced by the specific title can bereproduced starting from a random point. Conversely, the Normal Titleinformation should be played-back from a playback starting point of thedata being reproduced by the Normal Title information. In addition,referring to FIG. 3B, the auxiliary Title #m information of the indexfile includes designates a second chapter (Chapter 2) of Normal Title#k, and auxiliary Title #m-1 information included in the index filedesignates a third chapter (Chapter 3) of Normal Title #k. Morespecifically, among a plurality of chapters forming the title a randomchapter position is designated as the auxiliary Title information, so asto enable playback to start from the corresponding chapter.

Accordingly, in this detailed description, a “chapter” refers to a titlebeing divided into a plurality of playback units, and the chapterinformation is provided to the user. Therefore, the user uses a chapterskip-point during the playback of the current title, thereby being ableto skip to a different chapter within the current title. Morespecifically, a change (or shift) of chapter within a title that iscurrently being played-back (e.g., title #K) can be performed by usingthe chapter skip-point. And, during the playback of the current title(e.g., title #K), a change in chapter from the current title (e.g.,title #K) to a random chapter within another title (e.g., title #K+1,not shown) can be performed by using the auxiliary Title information.However, since the chapter has a different attribute from that of theobject, a single object may provide a plurality of chapters. And,alternatively, each of the objects may also provide each chapter. Morespecifically, the chapter is a set of playback unit information that isprovided to the user, and the object is a set of information that iscontrolled by the system and, thus, cannot be recognized by the user.

FIGS. 4 and 5 illustrate preferred embodiments of a method ofplaying-back the optical disc file according to the present invention.Herein, FIG. 4 illustrates an example of using an object mode, and FIG.5 illustrates an example of using a plurality of object modes, each ofwhich being different from one another. More specifically, FIG. 4illustrates a method of playing-back an optical disc file according to afirst embodiment of the present invention. FIG. 4 illustrates an exampleof a playback method using the Normal Title information and theauxiliary Title information within the index file, when only a singleobject mode is included, such as a Movie Object (hereinafter referred toas “M-OBJ”) for reproducing an image and a sound.

Referring to FIG. 4, when the user selects Normal Title #1 information,the object designated by the Normal Title #1 information (i.e., M-OBJ#1) is executed. As described above, the object (M-OBJ #1) is programmedby a group of various commands, which generally executes a specificPlayList, so as to perform playback functions of the data (i.e., AVstreams) that are related to the title. Furthermore, under specificconditions, the object (M-OBJ #1) may also include a command thatdesignates other objects. For example, when designating a second object(M-OBJ #2-2) among the objects related to Title #2 for playback, whilethe object (M-OBJ #1) related to Title #1 is executed by using theNormal Title #1 information, the second object (M-OBJ #2-2) can beplayed-back by using auxiliary Title #1 information, which includesinformation that corresponds to designating the second object (M-OBJ#2-2).

Moreover, when starting playback from the second chapter (Chapter 2)being related to Title #n, while an object (M-OBJ #1) related to Title#1 is executed by using the Normal Title #1 information, thecorresponding chapter (Chapter 2) can be played-back by using auxiliaryTitle #2 information having information that corresponds to designatingthe second chapter (Chapter 2). Additionally, when designating andplaying-back a first starting object (M-OBJ #I) that is related to theTitle #2, while the object (M-OBJ #1) that is related to Title #1 isexecuted by using the Normal Title #1 information, Title #2 may beplayed-back starting from the beginning by using the Normal Title #2information. More specifically, since the first starting object (M-OBJ#2-1) can be directly designated by the Normal Title #2 information, thefirst starting object (M-OBJ #2-1) is not necessarily required to bedesignated by using the auxiliary Title information. In other words,during the playback of a current specific title, playback may start froma specific point within a different title by using the auxiliary Titleinformation, more specifically, from a point within the mid-portion ofthe title, instead of the beginning of the title.

FIG. 5 illustrates a method of playing-back an optical disc fileaccording to a second embodiment of the present invention. Morespecifically, FIG. 5 illustrates an example of a playback method usingthe Normal Title information and the auxiliary Title information, when aplurality of object modes is included, for example, when a Movie Object(M-OBJ) reproducing image and sound, a Java Object (hereinafter referredto as “J-OBJ”) supplementing interactivity through enhanced data, and aWeb Object (hereinafter referred to as “W-OBJ”) being played-back as anHTML program, which is broadly used throughout the Internet, areincluded.

Accordingly, FIG. 5 only proposes an example of a variety of objectmodes, and another type of mode that is different from theabove-described object mode can be formed and used depending upon otherpreferred embodiments. And, therefore, the usage is not limited to aspecific object mode only. Also, as described in the file structure ofFIG. 1, when a plurality of object modes is included, the plurality ofobject modes may be controlled by a single object file (Object.bdmv) ormay each be controlled by a separate object file (MovieObject,JavaObject, and WebObject). More specifically, in the second embodimentof the present invention, when a plurality of object modes is providedand in case of playing-back different titles by a change or transitionbetween the object modes, the auxiliary Title information is used so asto facilitate the transition between the object modes.

Referring to FIG. 5, menu information included in an index tabledesignates a Java Object (e.g., J-OBJ #menu), each of Normal Title #1information and Normal Title #2 information designates a Movie Object(e.g., M-OBJ #1 and M-OBJ #2), Normal Title #3 information designates aJava Object (e.g., J-OBJ #3), and Normal Title #n information designatesa Web Object (e.g., W-OBJ #n). In an optical disc having theabove-described file structure recorded therein, when a “Menu Call”command is given by a user, a menu screen is displayed by using the JavaObject (J-OBJ #menu), thereby allowing the user to select a title (Title#1˜Title #n) by using a Menu button displayed on the screen.

Accordingly, a menu button that allows playback to be performed from amid-portion of a specific title is separately included in the presentinvention. For example, the user may select playback starting from aspecific chapter (e.g., chapter 3) within Title #2 (i.e., Title #2-ch3)by using the menu button. Thus, each of the objects (i.e., M-OBJ #1,M-OBJ #2, J-OBJ #3, and W-OBJ #n) being designated by each of the NormalTitle information are performed by a command selected by the user. And,when the user selects a menu button from the menu screen that startsplayback from a specific chapter (e.g., chapter 3) within Title #2(i.e., Title #2-ch3), the specific chapter within Title #2 is designatedby auxiliary Title #m information, so as to enable playback to startfrom the corresponding point.

Also, referring to FIG. 5, when the user selects Normal Title #3information and when the Java Object (J-OBJ #3) that is selected by theNormal Title #3 information is executed, a transition between objectmodes can be performed by using the auxiliary Title information. Forexample, the Movie object (M-OBJ #1-1 or M-OBJ #1-2) that is designatedby the Normal Title #1 information can be executed by using theauxiliary Title #1 information, and the Web Object (W-OBJ #n) that isdesignated by the Normal Title #n information can be executed by theauxiliary Title #2 information. Therefore, in the second embodiment ofthe present invention, transition may occur between object modes havingdifferent data attributes by using the auxiliary Title information.

FIG. 6 illustrates an optical recording and/or reproducing apparatusaccording to the present invention. The optical recording and/orreproducing apparatus 10 basically consists of a recording and/orreproducing unit 20, which includes a pick-up unit 11 for readingcontrol information including data and file information recorded withinan optical disc, a servo 14 controlling the operations of the pick-upunit 11, a signal processor 13 either recovering the playback signalreceived from the pick-up unit 11 to a desired signal value, ormodulating a signal to be recorded to an optical disc recordable signaland transmitting the modulated signal, a memory 15 temporarily storingand allowing usage of such control information, and a microcomputer 16controlling the above operations, and a controller 12 transmitting auser command and/or a system command to the recording and/or reproducingunit 20. Furthermore, an AV decoder 17 performs final decoding of outputdata depending upon the controls of the controller 12. And, in order toperform the function of recording a signal on the optical disc, an AVencoder 18 converts an input signal into a signal of a specific format(e.g., an MPEG-2 transport stream) depending upon the controls of thecontroller 12 and, then, provides the converted signal to the signalprocessor 13.

Accordingly, the controller 12 controls the recording and/or reproducingunit 20 and the AV decoder 17, so as to enable the playback of aspecific title (e.g., Title #1) that is selected by the user to beperformed. Also, while the title (Title #1) is being executed, a set ofauxiliary Title information within an index file, which designates arandom playback point of another title (Title #2) is used, therebycontrolling the recording and/or reproducing unit 20 and the AV decoder17, so that the playback point is changed (or shifted) to a random pointwithin the other title (Title #2).

As described above, the recording medium, the method of creating a fileof the recording medium, and the method and apparatus for reproducingthe same have the following advantages. Position change and transitionof random playback points among titles recorded within the recordingmedium can be easily performed, thereby providing to the users anapparatus having more convenient title playback functions.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A method of creating a file of a recording medium, comprising:forming a PlayList file including playback control information of a setof recorded data; forming an object file including an execute command ofthe PlayList file; and forming an index file including a set of NormalTitle information designating a specific object within the object file,and a set of auxiliary Title information designating a random point ofdata being reproduced by the Normal Title information.
 2. The method ofclaim 1, wherein a first object being designated by the Normal Titleinformation designates a second object.
 3. The method of claim 2,wherein the auxiliary Title information designates the second object. 4.The method of claim 1, wherein a plurality of titles being recordedwithin the recording medium is played-back by using the Normal Titleinformation.
 5. The method of claim 1, wherein each of the titlesincludes a plurality of chapters as a playback unit.
 6. The method ofclaim 5, wherein the auxiliary Title information designates a randomchapter point within a corresponding title.
 7. The method of claim 1,wherein the object file comprises at least one object file dependingupon a corresponding one of a plurality of object modes.
 8. The methodof claim 7, wherein each of the plurality of object modes comprises anindependent object file.
 9. The method of claim 1, wherein the NormalTitle information is executed by a user selection, and wherein theauxiliary Title information is automatically executed by a command fromthe object that is designated by the Normal Title information.
 10. Themethod of claim 1, wherein the Normal Title information and theauxiliary Title information are both executed by a user selection.
 11. Amethod of creating a file of a recording medium, comprising: forming anindex file for playing-back at least two titles within the recordingmedium including the at least two titles, wherein the index filecomprises: a plurality of sets of Normal Title information, wherein eachset of the Normal Title information is in a one-to-one correspondencewith each of the at least two titles recorded within the recordingmedium; and at least one set of auxiliary Title information enablingplayback of another title to be performed starting from a random pointof the title, while playing-back a specific title by using a specificset of the Normal Title information.
 12. A recording medium, comprising:a stream area having at least two titles recorded therein; and a filerecording area having an index file for playing-back the at least twotitles, wherein the index file comprises: a plurality of sets of NormalTitle information, wherein each set of the Normal Title information isin a one-to-one correspondence with each of the at least two titlesrecorded within the recording medium; and at least one set of auxiliaryTitle information enabling playback of another title to be performedstarting from a random point of the title, while playing-back a specifictitle by using a specific set of the Normal Title information.
 13. Therecording medium of claim 12, wherein at least one title each having adifferent attribute is recorded within the stream area, and wherein atleast one object file corresponding to each of the at least one titlehaving a different attribute is recorded within the file recording area.14. The recording medium of claim 13, wherein one of the at least oneobject file is a Movie Object file reproducing an image and a sound. 15.The recording medium of claim 13, wherein one of the at least one objectfile is a Java Object file reproducing enhanced data.
 16. The recordingmedium of claim 13, wherein one of the at least one object file is a WebObject reproducing an HTML program.
 17. A method for reproducing arecording medium, comprising: playing-back a first title by using a setof Normal Title information; and shifting to a random point of a secondtitle by using a set of auxiliary Title information, during the playbackof the first title, thereby reproducing the second title starting from acorresponding shifted point of the second title.
 18. The method of claim17, wherein, when the second title comprises a plurality of titles, theauxiliary Title information designates a random chapter point within thesecond title.
 19. An apparatus for reproducing a recording medium,comprising: an optical recording and/or reproducing unit playing-back atleast one title recorded within a stream area of the recording medium,and reading a set of Normal Title information and a set of auxiliaryTitle information recorded within a file recording area of the recordingmedium; and a controller controlling the optical recording and/orreproducing unit, so as to play-back one of the titles recorded withinthe recording medium by using the Normal Title information, and toplay-back another title starting from a random point by using theauxiliary Title information.